Apparatus for the heating of liquids



July 31, 1956 M. SANTONI 2,757,272 APPARATUS FOR THE HEATING OF LIQUIDS Filed Jan. 14, 1955 4 Sheets-Shae tl 7 5 INVENTOR.

Mariano Santoni BY {Ma Wm,

ATTORNEY.

July 31, 1956 M. SANTONI APPARATUS FOR THE HEATING OF LIQUIDS 4 Sheets-Sheet 2 Filed Jan. 14, 1955 July 31, 1956 M. SANTONI 2,757,272 APPARATUS FOR THE HEATING OF LIQUIDS Filed Jan. 14, 1955 4 Sheets-Sheet 4 FL 0 W RESPONSIV DEVI c: 59 ll ACTUATOR INVENTOR. Mar mrzo Suntan 1 A TTORNEY.

United States Patent APPARATUS FOR THE HEATING or movies Mariano Santoni, Santurce, Puerto Rico Application January 14, 1955, Serial No. 481,854 21 Claims. (Cl. 219-40) This invention relates to a method and apparatus for the heating of liquids by electrical conduction.

It is a principal object of the present invention to provide an electric water heater wherein the available space between the electrodes through which the Water to be heated is circulated may be readily and easily adjusted from the outside of the device and wherein a finer adjustment of this type than heretofore attained is provided. The present invention permits a wide range of adjustment to meet varying water and temperature conditions.

it is another object of the present invention to provide an electrical heater of the above type wherein the water emerging from the heater is maintained at ground potential to eliminate the possibility of electrical shock, this being efiected by the grounded inlet and outlet nipple at the end of the heating chamber.

It is still another object of the present invention to provide an electrical switching device of the above type wherein the pole pieces of the rotor electrode may be adjusted so as to vary the space between the pole pieces and the stator electrodes in a novel manner.

It is another object of the present invention to provide an electrical heater of the above type wherein safety switch means are included for automatically turning the current through the heating chamber upon the arising of abnormal steam conditions therewithin or in the event that the primary flow responsive switching means is unable to operate properly.

Other objects of the present invention are to provide an electrical heater bearing the above objects in mind which is of simple construction, inexpensive to manufacture, has a minimum number of parts, is easy to use and efiicient in operation.

For other objects and a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which:

Figure l is a perspective view of a preferred embodiment of the present invention;

Fig. 2 is a front elevational view thereof showing the exterior casing in section;

Fig. 3 is a bottom plan view thereof taken along the line 33 of Fig. 2;

Fig. 4 is a vertical sectional view thereof as taken along the line 44 of Fig. 2 and showing the flow switch in the closed position;

Fig. 5 is a transverse sectional view thereof taken along the line 55 of Fig. 4;

Fig. 6 is a transverse sectional view thereof taken along the line 6-6 of Fig. 4;

Fig. 7 is a top plan view of a safety switch forming a part of the invention taken along the line 7-7 of Pig. 4;

Fig. 8 is an enlarged fragmentary vertical sectional view similar to Fig. 4 but showing the flow switch and safety switch in the open positions;

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Fig. 9 is a fragmentary front view showing the safety switch in elevation and the flow switch in section;

Fig. 10 is a vertical sectional view taken along the line 1tl-10 of Fig. 5;

Fig. 11 is a top plan view of the device with the exterior casing removed;

Fig. 12 is a schematic diagram of the electrical circuit connections for the apparatus; and

Figs. 13 and 14 are schematic diagrams of alternate electrical circuit connections for the apparatus.

Referring now more in detail to the drawing, an electrical heating apparatus embodying the features of the present invention is generally indicated by a heater assembly it and a flow responsive electrical switching device 11 and a flow responsive safety switching device associated therewith.

The heater assembly 10 comprises a water heating chamber formed by an open ended outer casing 13 of a suitable metal such as copper and of cylindrical shape, the ends of the casing 13 being enclosed by discs 14 and 15 formed of lava stone. A water-tight seal intermediate the discs 14, 15 and the casing 13 is formed by the 0 seal rings 16 and 17. The heater assembly is rigidly held together by a pair of tie rods 18 (Fig. 5 the externally threaded ends of which extend through suitable openings in the discs 14 and 15 to receive thereon the nuts 19.

Concentrically disposed within the heater chamber (Fig. 5) is an electrode structure consisting of a rotor electrode indicated generally at 2%} and a segmental stator electrode made up of a plurality of stator sections 21, 22, 23 and 24. The stator sections 21, 22, 23, 24 are arranged circumferentially at equally spaced positions about the rotor electrode 29 and are spaced therefrom to define the annular water passage 25, the stator sections being formed of carbon or graphite strips and having an arcuate cross section whose curvature corre sponds to that of the faces of the rotor electrode. The ends of the stator sections 21, 22, 23, 24 are mounted within circular grooves 26 and 27 provided in the inner faces of the discs 14 and 15, respectively.

The electrode 20 includes a bushing 28 which extends upwardly through a centrally disposed bore 29 in disc 14, the lower end of the bushing 28 being integrally formed with a lateral flange 30 limiting upwardly displacement of the bushing through the disc. The upper end of the bushing extends upwardly through the disc in an externally threaded portion 31 which receives thereon a nut 32 whereby to limit the downward displacement of the bushing through the disc in an obvious manner, an O ring seal 33 being provided intermediate the bushing 28 and disc 14 to provide a water tight seal. A shaft 34 is rotatably mounted within the bushing 28 and includes an enlarged head 35 having a slot 36 adapted to receive therein a screw driver or the like for effecting the rotation of the shaft 34 for a purpose which will hereinafter become clear. The lower end of the shaft 3 is integrally formed with an enlarged portion 37 forming therewith a shoulder which abuts the flange 39, the enlarged portion 37 having an internally threaded bore 38 extending upwardly from the lower end thereof.

A supporting shaft 39 is integrally formed at its upper end with an enlarged externally threaded portion 49 which is adjustable within the internally threaded bore 38, the shaft 39 at its lower end being provided with the cylindrical enlargement 41.

A pair of interlocking rectangular plates 42 and 43 intersecting each other at right angles are positioned at their upper ends within a pair of transverse, intersecting slots extending upwardly from the bottom of the cylindrical enlargement 41, being secured therein in suitable manner whereby to support the plates.

A bushing 44 of non-conductive material and having a central bore 45 extending therethrough is formed on its upper end with a pair of intersecting transverse slots which receive therewithin the lower ends of the intersecting plates 42, 43, the lower end of the bushing 44 extending into a central bore 46 provided in the disc 15. Thus, upon the rotation of shaft 34 by means of a slot 36 at the external upper end thereof, the externally threaded enlargement 49 of shaft 39 will be adjusted vertically within the internally threaded bore 38 of bushing 28 and shaft 34 whereby to raise and lower the intersecting plates 42, 43 slidably mounted at their lower ends by means of the bushing 44. Each of the plates 42, 43 is provided along the opposite vertical edges thereof with a vertically spaced, downwardly and inwardly extending pair of slots 47.

The rotor electrode 20 also includes four symmetrically arranged members, each of which includes a body portion 48 integrally formed along its outer face with an arcuate pole piece 49, the body 48 and pole piece 49 being formed of carbon or graphite. Each of the body portions 48 at its upper end on the inner face thereof is provided with a recessed portion 56 and at the lower end thereof with a second recessed portion 51 (Fig. 4). Each of the body portions 48 is further provided with a vertical slot 52 extending from end to end, the slot 52 terminating short of the outer face of the pole pieces 49 and snugly and slidably receiving therewithin one side of the plates 42, 43. Each of the body portions 48 is provided with a pair of vertically spaced pins 53 which extend through the slots 52 and which ride in the grooves 47 (Fig. It will be noted that the upper end of the pole pieces 49 abut the under surface of lava or stone disc 14. Thus, upon rotation of shaft 34 in one direction by means of the slot 56 and a screwdriver or the like, the supporting shaft 39 and plates 42, 43 will be drawn upwardly, which action moves the pins 53 inwardly within slots 47 whereby to. increase the distance between the pole pieces. 49. and the stators 22, as shown in full lines in Fig. 5. However, upon rotation of the shaft 34 in the opposite direction, the plates 42, 43 will be lowered (the bushing 44. moving downwardly within bore, 46) which causes the pins 53 to move outwardly and to move the pole pieces 49 towards the stators 22, as shown in dotted outline in Fig. 5. Thus, the distance between the pole pieces and stators may be adjusted. Furthermore, when the pins 53 are in either extreme position, further rotation of the shaft 34 will cause the pole pieces 49 to rotate relative to the stators 22 from a point they are exactly in register to a point at which they are out of register, providing an additional adjustment.

An outlet pipe 54, (Fig. 4) is provided for the heating chamber, the pipe extending through an opening in one side of disc 14 and being secured thereto by a nut 55. Pipe 54 is internally threaded for coupling with the aid of a suitable hose 56 to a conventional water valve or spigot, not shown.

As shown in Fig. 11, the upper end of one of the tie rods 18 is electrically connected to the pipe 54 with the aid of a flat metal link 57 while the upper end of the other tie rod 18 is electrically connected to the bushing 28 by means of a second flat metal link 58.

A flow responsive electrical switching device 111 is mounted below disc on the heating assembly 110 and generally comprises a flow chamber 59 formed by a hollow metal cylinder, an insulating collar 66 surrounding said cylinder and adapted to support a plurality of electrical switching units, and a common actuator for said units constituted by an insulating cap 61 slidably mounted on the lower end of chamber 59 and coupled to a plunger 62 slidably disposed within the flow chamber. Axial displacement of the flow chamber 59 relative to the collar 60 is prevented by means of a split ring 63 fitting into a circular groove adjacent the upper end of the chamber.

The interior of flow chamber 59 is stepped in diameter to thus define a lower section 64 of relatively small diameter, an intermediate section 65 and an upper section 66 of larger diameter, a beveled shoulder 65a being formed between bore sections 65 and 64, and a shoulder 66a being formed between bore sections 66 and 65. Plunger 62 is preferably machined from a single piece of metal, such as brass, having a circular cross section to form at one end a disc shaped head 67 whose lower face is beveled. The diameter of head 67 is slightly smaller than that of intermediate section 65 to provide a clearance therebetween in the order, for example, of 0.002 inch, whereby the head is slidable within section 65 which is to an extent limited in the downward direction by shoulder 65a. The other end of plunger 62 is shaped to define a mounting post 68 upon which the actuator cap 61 is supported, an O-ring 69 being provided on the post 63 below cap 61.

The piston 62 is provided with an O--ring 70 which forms a water-tight seal with the reduced bore 71 which connects with the lower end of the bore 64.

The piston 62 is provided with an upper bore 72 of relatively large diameter which communicates with a lower bore 73 along a beveled shoulder 74, the bore 73 extending downwardly through the post 63 and slidably mounting a plunger rod 75. The upper end of the plunger rod 75 is integrally formed with an enlarged plunger 76 slidable within bore 72, an O-ring seal 77 being provided on the plunger 76 whereby to form a water-tight seal be tween the latter and bore '72. A collar 78 is secured to the lower end of the plunger rod 74 by means of a set screw 79 for a purpose which will hereinafter become clear.

As shown in Fig. 9, an inlet to the flow chamber 59 is provided by means of internally threaded bore 80 opening into chamber section 64 and an externally threaded inlet pipe 81, the insulator collar 60 being provided with a cut out or opening 82 which receives therethrough the pipe 81. i

The upper section 66 of the flow chamber 59 is connected to the inlet bore 46 of the heating chamber by means of a coupling member 83' positioned therewithin and provided with a lower flanged portion 84 which is received within section 66 and is provided with an 0- ring 85 eifecting a water-tight seal therebetween. The coupling member 83 is secured to the disc 15 by means of a nut 56.

As shown in Fig. 3, circumferentially arranged and supported on collar 60 are a plurality of individual contacts switching units 37', 68, 39, 9G and 91. The angular positions of units 87, 88, '89 and 91 correspond to that of the stator electrode sections. 21, 22, 23 and 24, while the angular position of unit corresponds to that of one of the tie rods 18. Switching units 87, 88, 39 and 91 are of identical construction and therefore only one will be described in detail. Each of these units comprises an L- shaped metal strip 92 supporting a contact 93, and a flat spring finger 94, carrying a contact 95 in coacting relationship to the contact 93. The contacts 93, 95 are preferably formed of silver. The lower portion. of each of the fingers 94- is bent so as to provide a V-shaped projection 94a whose apex faces the outer wall of the actuator cap 61.

Each of the contacts 93 functions as the stationary contact of the switching unit and is connected to the associated stator by means of an internally threaded metal sleeve 96 inserted in suitable apertures in disc 15 and the stators, a screw 97. connecting the upper horizontal portion of each of the strips 92 to the lower end of the sleeves 96.

Contact 95, which co-acts with contact 93, functions as the movable contact of each of the switching units. All movable contacts in units 87, 88, 89, 91 are electrically connected together by means of a circular metal strap 93 which bridges the spring fingers 94 of these units. Thus, by means of a lead 99 (Fig. 12) connected to one terminal of the safety switch 12 to be hereinafter described and which is in turn connected to a source of voltage, a connection is completed by the individual switching units 87, 8-8, 89 and 91 to the stator electrodes 21, 22, 23 and 24.

The remaining switching unit 90 serves to effect a connection from the other terminal of safety switch 12 to the rotor electrode 21 The switching unit 90 includes an L-shaped strip Mitt bearing a stationary contact 1M which is connected in series by means of the tie rod 18, flat conductor 58 and bushing 23 to rotor electrode 20. A movable contact 102 in co-acting relation with contact 161 is carried by flat spring finger 103 bent at its lower end to deine a V-shaped projection 163a whose apex also abuts the outer wall of the actuator cap 61. Thus, by extending a lead 194 from the other terminal of the safety switch 12 to spring finger 103, a connection is completed via switchin unit 99 to rotor electrode 20.

The spring fingers of each of the switching units 87 through 91 are biased whereby to urge the associated movable contacts into engagement with the corresponding fixed contacts. It will be noted (Fig. 2) that the projections in switches 87, 88, 89 and 91 depend at the same level, whereas the projection 193a extends slightly downwardly therebeyond. The opening and closing of each of the switching units is governed by the vertical position of the actuator cap 51, the cap having a switch closed position shown in Fig. 4, and a switch open position shown in Fig. 8.

The actuator cap 61 is shaped so as to provide a lower portion or crown 51a of reduced diameter which conmeets with an upper rim portion 61c of relatively large diameter by means of a frusto-conical intermediate portion 61!). As will hereinafter become clear, by means of the movement of plunger 62 the cap assumes the switch open position of Fig. 8, when the spigot or valve 1115 connected to inlet pipe 81 (Fig. l) is closed, and is forced upwardly to the valve open switch closed position of Fig. 4 when the valve 105 is open. In the switch closed position of the cap, the apex of the finger projections 94 and 103a of the various switching units lie adjacent but not abutting the reduced portion 61a of the actuator cap. Hence, in this position, all of the switching units are closed. When, however, the actuator cap 61 is forced downwarr'ly, the spring finger projections 94a and 103:: are engaged by the enlarged portion 61c whereby to force the spring fingers outwardly and breaking the switch contacts. inasmuch as the projection 1433a of the unit 90 extends downwardly beyond the projections 94a of the other units, it is tr e last to be engaged by the downward movement of cap 6.1. As a result, the switching units 87', S8, 89 and 91 are first opened simultaneously, which operation is t; en followed by the opening of the switching unit 9%.

The safety switch 12 includes a mounting or body portion 196 of non-conductive material provided along its f ont face with three laterally, spaced, vertically extending grooves 13*7, 1113 and 1G9.

A pair of L-shaped strips 11h are mounted within the groove 1117 in vertically spaced relationship by means of the screws 111. A similar pair of vertically spaced L- shaped strips 112 are mounted within the groove 109 by means of the screws 113, the free ends of the strips 112 and 111? being aligned laterally, as shown in Fig. 9.

A cylindrical bearing member 114 is provided at one end with an elongated plate 115 which is fixedly mounted within the groove 1118 by means of the screws 116. The free end of the bearing member 114 on opposite sides is provided with a pair of laterally aligned, inwardly extending slots 117 which are in turn aligned with the spaces intermediate the horizontal portions of the vertically spaced brackets 110, 112. A transverse pin 118 pierces one end of a plunger rod 119 slidable within the cylindrical member 114, the pin 118 extending outwardly through the slots 117 and fixedly mounting on the ends thereof the cylindrical enlargements 120 which are resiliently received intermediate the spaced ends of the strips and 112 whereby to form electrical contact therewith, the strips 110, 112, cylindrical casing 114, strip and plunger rod 119 being formed of electrically conductive metal, as is the pin 118 and the cylindrical enlargements 120. The plunger rod 119 at the outer end thereof fixedly carries the enlarged knob portion 121 and is normally retained in the switch open position by means of a spring 122 which sleeves the rod 119 intermediate the knob 121 and the end of the casing 114, as shown in Fig. 7. The switch 12, however, is normally retained in a closed position against the action of spring 119 by means of a channel shaped member 123 having stepped sides 124 and which is connected at its inner end to the undersurface of the casing 114 by means of a bolt 125 passing upwardly therethrough, the bolt 125 extending upwardly above the casing 114 in an externally threaded portion 126. A collar 127 is positioned on the lower end of the externally threaded portion 126 and abuts the lower end of the spring 128, the upper end of which engages a collar 129 screwed downwardly onto the externally threaded portion 126. Thus, by adjustment of the internally threaded collar 129, the tension of the spring 128 may be regulated and thereby the amount of pressure necessary to lower the channel shaped member 123 to the switch open position of Fig. 8.

The side walls 114 are formed with the shoulders 130 which are adapted to abut the pin 113 whereby to retain the latter and the cylindrical contacts 120 in the switch closed position of Fig. 4 against the action of spring 122. However, upon the depression of the collar 78 carried by the plunger rod 75 as will hereinafter become clear, the

channel shaped member 123 will be rotated downwardly t to the position of Fig. 8 to move the shoulder 130 out of engagement with pin 118 and to permit the latter and the cylindrical contacts 120 to move to the switch open position of Fig. 8 under the action of the spring 122.

The connector member 83 is electrically connected to one of the tie rods 18 by means of a flat conductor, not shown.

A ground lead 131 extends from the plate 115 to one of the tie rods 18.

The external voltage supply may be connected to the heating apparatus in various ways, depending upon the nature of the available current; i. e., whether it is direct, single phase or two phase of alternating current.

When the valve 105 is opened, the actuator cap 61 is caused to assume its switch closed position (Fig. 4), wherein all of the switching units 87, 88, 89, 90 and 91 are closed to establish an electrical field between the rotor electrode 20 and each of the stator electrode sections 21, 22, 23 and 24. This produces an electric current flow in the water passing between the electrodes and entering the inlet pipe 81 and leaving by outlet pipe 56 whereby to heat the water to an extent depending upon the magnitude of the voltage and the spacing and effective area of the opposing electrodes. This current flow is evenly distributed in parallel relation among the stator electrodes 21 through 24. It will be readily understood that while the four stator sections have been illustrated, a greater or smaller number may be employed and in cooperation with a rotor possessing an equal number of poles.

When the valve is closed, the resultant pressure in the flow chamber 59 lowers the actuator cap 61, effecting the opening of the contacts of switches 87, 88, 89 and 91 and followed shortly thereafter by the opening of the contacts of switching unit 90. By this arrangement the interruption in the current flow from one terminal of the voltage supply to the stator sections precedes that from the other terminal of the voltage supply to the rotor electrode reducing further the tendency towards arcing.

Upon the opening of the safety switch 12 as will hereinafter become clear, the current will. also be, broken even. though the switching elements 87, 88, 89, 90 and 91 remain closed. For example, in the event of failure of the flow responsive switch 11.

Figs. 13 and' 14 illustrate alternate arrangements for connecting the safety switch 12 to a voltage supply.

In operation, when. the valve 105-connected to the cold water line is opened, the water supplied through the inlet pipe 81 enters the flow chamber 59 and passes via the coupling member 83 into the heating assembly in where it flows into channelZS between rotor electrode and the stator electrode sections 21 through 24 to be heated by electrical, conduction. The heated water is then dis charged through the outlet pipe 56.

If the water entering the apparatus is, for example, at a pressure of pounds per square inch and the valve 105 is, closed, all parts of, the heater assembly lit in the flow chamber 59 will contain water in a stationary condition at a static pressure of 40 pounds per. square inch. Under these conditions, the pressure imposed on both sides of the plunger head 67 is equal since there is a clearance between the head and the wall of section 65. However, the, pressure exerted on the lower face. of the head 67 affects only an annulus region whereas the pressure, operating upon the upper face of the head affects the entire disc-shaped area, including the central portion thereof. Under these conditions, the plunger 62 and the actuator cap 61 are lowered downwardly so that they assume the position shown in Fig. 8, due to the fact that they pressure of 40 pounds per square inch on the central area of the piston or plunger head is greater than the outside atmospheric pressure on the end of the plunger. When the valve 105 is open and water begins to flow, the pressure in the flow chamber 59 drops. As a result, the 40 pounds per square inch pressure on the lower face of the head 67 pushes the plunger 62. upwardly until there is a clearance between shoulder 65a and head 67 sufficient to allow full flow of water at that point. When the valve is again. closed with the plunger in the position of Fig. 4, pressure equalizes on both sides of the piston head and once again the 40 pounds per square inch pressure on the central area of the upper face of the head operating against the outside atmospheric pressure forces the plunger back to the position of Fig. 8, thus simultaneously cutting off the flow of electricity with the supply of the water.

It will'be apparent, from the foregoing, that when one opens the valve, the voltage supply will automatically be connected to the heater electrodes through the normally closed switch 12 so that the Water discharged from the outlet pipe 56 is heated. And when one closes the valve, the operating voltage is automatically shut off. This feature is of particular convenience where frequent and repeated use is made of the water heater.

To adopt the heater apparatus in accordance with the invention to installations in regions where the water supply differs materially in salt content and hence in resistivity, one has merely to adjust by means of a screw driver the distance between the rotor electrode 20 relative to the stator sections as well as the angular position of the rotor electrode element 20 relative to the stator sections. Thus, by permitting both lateral and angular adjustment of the pole pieces of the rotor electrode, a finer adjustment is possible than heretofore attained. Adjustment may also be made toobtain a desired water temperature by means of the aforesaid. two variables.

If for any reason an abnormal steam pressure is produced in the heater, the safety switch 12. provided will automatically open thev circuit. Thus, due to the piston fit between the head 76 carrying the O-ring 77 and the bore. 72 of the plunger, any generated steam pressure will force the: plunger rod 75 downwardly carrying thereal'ong. the collar 78. As the collar 78 moves downwardly, it

contacts the channel-shaped member 123' and moves the latter from the switch closed position of Fig. 4 to the switch open position of Fig. 8 to permit the outward movement of the plunger rod 119 under the operation of spring 122 which movement draws the cylindrical contacts 120 out of contact with the plates 110, 112 and breaking the circuit thereby. To put the heater back in operation, it is only necessary to open the valve and press the knob 121 towards the base plate 106 of the switch. If the safety switch 12 trips several times, a qualified service man should be called to locate the trouble within the system.

The entire assembly is suitably mounted Within an outer casing 135' having a suitable opening receiving the inlet pipe 81 and outlet pipe 56 therethrough, the casing 135 being mounted upon the wall or the like by means of the flanges 136 and screws 137 (Fig. 1).

Electrical connections: For connection to a volt line, when the water is obtained from an elevated tank not having any ground connection, the hot wire from the line is connected to the lowermost screw 113 (the terminal marked 4 in Fig. 12). The neutral wire of the line is connected to the terminal marked 6 or the lowermost screw 111, the terminals 5 and 6 being joined (i. e. the lowermost screw 116 is connected to the line extending from the lowermost screw 111).

For connection to a 220 volt line, when the water is obtained'from city mains, the two hot wires are connected to theterminals marked 4 and 6 (Fig. 13), each of the hot Wires carrying 110 volts. In this case, the terminal marked 5 is not used.

For connection to a 220 volt line, when the water is obtained from an elevated tank, not having any ground connection, the two hot wires each carrying 1 10 volts,

are connected to the terminals marked numbers 4 and 6 (Fig. 14). In this case the terminal marked 5 is grounded.

For connection to a 110 volt line, where the water is obtained from city mains, the hot wire from the line is connected to the terminal marked number 4, while the neutral wire of the line is connected to the terminal marked number 6. The terminal marked number 5 is not used in this case.

If the heater is to be connected to a single phase 220 volt line, the arrangement of Fig. 12 may be employed.

Setting of heater: The heater when shipped will have the inner elements so adjusted that there is a maximum space between them and the outer elements. Therefore, the current first drawn by the heater will be of low value. To obtain the desired temperature, proceed as follows:

1. Connect an ammeter in the line;

2. open the valve 105 g 3. read the arnmeter;

4. adjust the clearance between the inner and outer carbon elements by turning with an insulated screw driver the current adjusting shaft 34; the casing being provided with an opening 138 for this purpose. The shaft 34 is rotated counter-clockwise until the current increases to the desired value, care being taken not to exceed the capacity of the fuse being used.

Tests have shown that the heater consumes one kilowatt hour for every ten gallons of water raised forty degrees F. in temperature.

It will be noted that the fiow switch will be adjusted so that if a hot water'fau'cet or valve 105 is only slightly opened, electrical contact will not be made. However, it will be noted that if the water flow is reduced to a very small quantity, the heater may generate steam. If for any reason an abnormal steam pressure is produced, as mentioned above, the safety switch 12 will open the 'cirouit. The safety switch will also function in the event that the flow switch becomes jammed for any reason.

While various changes may be made in the detail con struction, it shall be understood that such changes shall be within. the spirit and scope of the present invention as defined by the appended claims.

What is claimed is:

1. An apparatus for heating fluid by electrical conduction comprising spaced electrode means forming a fluid passage, circuit means including an electrical switch, means to establish a potential difference between said electrode means whereby to produce a heating current in fluid flowing through said passage, means responsive to said fluid flow to actuate said switch means to disconnect said electrode means upon cessation of said fluid flow, said circuit means further including safety switch means, and means responsive to abnormal pressure Within the device to actuate said safety switch means to disconnect said electrodes.

2. An apparatus for heating fluid by electrical conduction comprising a heating chamber having an inlet and an outlet, spaced electrodes disposed within said heating chamber to form a water or fluid passage extending between said inlet and outlet, a flow responsive device including a flow chamber, means for transmitting fluid to the heater via said flow chamber into said inlet, means including an electrical switch connecting said spaced electrodes to a voltage supply, an actuator operatively coupling said device to said switch to disconnect said electrodes from said supply when the fluid in said flow chamber is stationary and to connect said electrodes with said supply when said fluid is flowing, said means further including a safety switch connecting said spaced electrodes to a voltage supply, and actuating means responsive to abnormal pressure within the apparatus operatively coupling said device to said safety switch to disconnect said electrodes from said supply when the pressure within the apparatus exceeds a predetermined value.

3. iressure and flow responsive apparatus for heating fluid by electrical conduction comprising a heating chamber, spaced electrodes disposed within said heating chamher to form a fluid passage therebetween, a flow responsive device including a flow chamber, means transmitting the fluid to be heated through said flow chamber and into said heating chamber, circuit means including an electrical switch connecting said spaced electrodes to a voltage supply, means coupled to said device for actuating said switch to disconnect said electrodes from said supply when the fluid in said flow chamber is stationary, said circuit means further including a safety switch connecting said spaced electrodes to a voltage supply, and means responsive to abnormal pressure within the apparatus coupled to said device for actuating said safety switch to disconnect said electrodes from said supply when the pressure within the device exceeds a predetermined value.

4. A pressure and flow responsive electrical water heating apparatus comprising a water heater assembly including an inlet, an outlet and spaced electrodes forming a water passage between said inlet and outlet, a flow responsive device including a flow chamber having an inlet adapted to be coupled to a water supply and an outlet, the outlet of said flow chamber being coupled to the inlet of said assembly, a plunger slidable within said fluid chamber to occupy as a function of the water pressure therein a first position in the condition when said fluid is flowing and a second position when said fluid is stationary, circuit means including an electrical switch connecting said electrodes to a voltage supply, an actuator supported on said plunger for movement therewith and operatively coupled to said switch to effect a switch closing action in said first position and a switch opening action in said second position, said circuit means further including a safety switch connecting said electrodes to a voltage supply, said plunger having a central longitudinal bore connecting said fluid chamber with the atmosphere, and a piston slidable within said bore and in operative engagement with said safety switch whereby to open said safety switch when the pressure within said fluid chamber reaches a predetermined value.

5. An apparatus for heating fluid by electrical conduction comprising a heating chamber having an inlet and an outlet, spaced electrodes disposed within said heating chamber to form a fluid passage extending between said inlet and said outlet, a flow responsive device including a flow chamber, means for transmitting fluid to the heater via said flow chamber into said inlet, means including electrical switch connecting said spaced electrodes to a voltage supply, an actuator operatively coupling said device to said switch to disconnect said electro es from said supply when the fluid in said flow chamber is stationary and to remake said connection when said fluid is flowing, said heating chamber including end walls of non-conductive material and means connecting said end walls of non-conductive material.

6. An apparatus for heating water by electrical conduction comprising a heater chamber, a plurality of inner electrodes disposed within said heating chamber, a plurality of outer electrodes disposed about said inner electrodes and spaced therefrom to form a water passage, said inner electrodes being adjustable laterally and angularly relative to said outer electrodes, a flow responsive device having a flow chamber, conduit means to feed water to the heater via said flow chamber into said heating chamber, a voltage supply provided with first and second terminals, means including a switching element to connect said inner electrodes to said first terminal, means including an individual switching unit connecting each of said outer electrodes to said second terminal, means coupled to said device and operative when the fluid in said flow chamber is stationary for first actuating said switching unit simultaneously to disconnect said sections from said second terminal, and thereafter actuating said switching element to disconnect said inner electrodes from said first terminal, and means for adjusting said inner electrodes laterally with respect to said outer electrodes whereby to vary the distance therebetween.

7. An apparatus for heating water by electrical conduction comprising a heating chamber, a plurality of inner electrodes disposed within said heating chamber, a plurality of outer electrode sections disposed about said inner electrodes and spaced therefrom to form a water passage, a flow responsive device having a flow chamber, conduit means to feed water to the heater via said flow chamber into said heating chamber, a voltage supply provided with first and second terminals, means connecting said inner electrodes to said first terminal, means including an individual switching unit connecting each of said outer electrode sections to said second terminal, means coupled to said device for actuating said switching unit simultaneously to disconnect said sections from said second terminal when the fluid in said flow chamber is stationary, safety switch means connected to said inner and outer electrodes, and pressure responsive means for actuating said safety switch and actuable upon abnormal pressure within said flow chamber.

8. In an electric water heating apparatus, an electrode structure comprising a cylindrical rotor electrode formed from a plurality of separable, symmetrically arranged pole pieces, a stator electrode concentrically disposed about said rotor electrode and constituted by a plurality of distinct stator sections, and means for simultaneously adjusting the position of said pole pieces relative to said stator sections laterally and angularly.

9. Pressure and flow control apparatus for automatically heating water by electrical conduction comprising a heating chamber, a rotor electrode disposed within said heating chamber and provided with a plurality of symmetrically arranged pole pieces, a like plurality of complementary stator electrode sections disposed circumferentially about said rotor electrode and spaced therefrom to define an angular water passage in said heating chamber, circuit means including individual switching unit connected to each of said stator sections to establish a potenial difference between said rotor electrode and said stator sections, means responsive to the flow of water in said passage simultaneously to disconnect said units upon cessation of said flow and pressure responsive means simultaneously to disconnect said units upon the rise of pressure within the apparatus beyond a predetermined value.

10. In an electric water heating apparatus, a heating chamber, a cylindrical rotor electrode disposed within said chamber and provided with a plurality of separable, symmetrically arranged pole pieces, a shaft extending without said chamber and rotatably mounted thereon, a plurality of intersecting supporting plates adjustable on the inner end of said shaft upon rotation of the latter, each of said plates having downwardly and inwardly extending slots extending inwardly from the vertical edges thereof, and pins fixedly carried by each of said pole pieces and riding within said slots whereby to vary the lateral distance between said pole pieces and said chamber upon rotation of said shaft, a like plurality of complementary stator sections disposed within said chamber and circumferentially arranged about said rotor electrode in spaced relation with said pole pieces, and end walls of non-conductive material closing the ends of said heating chamber.

11. In an electric water heating apparatus, a carbon electrode structure comprising a cylindrical rotor electrode made up of a plurality of symmetrically arranged pole pieces, a like plurality of complementary stator sections circumferentially arranged about said rotor electrode and spaced therefrom to form an annular water passage, said sections being formed by a strip having an arcuate cross section, means for mounting and adjusting said pole pieces laterally and angularly relative to said stator sections, and opposed end walls fixedly mounting the ends of said stator sections.

12. In an electrical water heating apparatus, a heater assembly comprising an open-ended cylindrical outer casing, first and second discs enclosing the ends of said casing to define a heating chamber, an electrode structure disposed within said chamber and including a cylindrical rotor electrode provided with a plurality of separable, symmetrically arranged pole pieces, means for mounting and adjusting said pole pieces laterally and angularly, a like plurality of complementary stator sections circumferentially arranged about said rotor electrode in spaced relation therewith to form an annular water passage, a shaft rotatably mounted within one of said discs and projecting outwardly therethrough, a plurality of intersecting supporting plates adjustably mounted on the inner end of said shaft and adjustable upon rotational movement thereof, each of said plates having angular slots extending inwardly therefrom from the outer edges, pins fixedly carried by each of said pole pieces and riding within said slots whereby to vary the lateral position of said pole pieces relative to said stator sections upon rotation of said shaft, an outlet extending through said one of said discs, an inlet extending through the other of said discs, means for grounding said rotor electrodes, and said stator sections, said discs being formed of lava stone, a flow responsive device mounted upon the other of said discs and including a flow chamber communicating with the inlet to said heating chamber, inlet means to couple the water supply to said flow chamber, a plunger slidable within said flow chamber and adapted to occupy a longitudinal position therein depending upon water flow, switching means to connect said electrodes to a voltage supply to establish a potential difference between said rotor electrode and said stator sections, an actuator coupled to said plunger and movable therewith, said actuator being operatively coupled to said switching means to disconnect said electrodes when the water in said flow chamber is stationary, safety switch means connecting said electrodes to a voltage supply, said plunger having a longitudinal bore connecting said flow chamber with the atmosphere, and a piston slidable within said bore and in opera'tive engagement with said safety switch whereby to open said safety switch means upon the build up of abnormal pressure within the apparatus or failure of said flow responsive device.

13. In an electrical water heating apparatus, a heater assembly comprising an open ended cylindrical outer casing, first and second discs enclosing the ends of said casing to define a heating chamber, an electrode struc ture disposed within said chamber and including a cylindrical rotor electrode provided with a plurality of separable, symmetrically arranged pole pieces, means for mounting and adjusting said pole pieces laterally and angularly relative to said shell, a like plurality of complementary stator sections circumferentially arranged about said rotor electrode in spaced relation therewith to form an annular Water passage, a shaft rotatably mounted in one of said discs and extending outwardly therefrom, a plurality of intersecting supporting plates adjustable longitudinally on the inner end of said shaft upon rotation of the latter, each of said plates having downwardly and inwardly extending vertically spaced slots extending inwardly from the outer edges thereof, pins fixedly carried by each of said pole pieces and riding said slots whereby to adjust said pole pieces laterally relative to said stator sections upon rotation of said shaft, an outwardly extending outlet extending through one of said discs, an inlet extending through the other of said discs, means for grounding said rotor electrodes and said stator sections, said discs being formed of lava stone.

14. Apparatus according to claim i2, said flow chamber comprising a cylinder having an internal bore stepped in diameter to form the first section of relatively small diameter and a second section of larger diameter, said inlet means for said flow chamber communicating with said first section, said second section communicar iug with the inlet of said heating chamber, said plunger.

slidable within said flow chamber being provided with a disc shaped head portion whose diameter is greater than the diameter of said first section and slightly smaller than that of second section whereby said head is adapted to reciprocate within said second section, the movement of said plunger being governed by the water pressure difference above and below said head, said bore extending through said disc-shaped head, said plunger including a piston slidable within said bore and a piston rod extending outwardly therefrom and terminating in an enlarged collar adapted to actuate said safety switch means upon downward movement thereof.

15. A method of heating fluid by electrical conduction comprising the steps of conducting electric current across a passage for the flow 'of fluid formed between oppositely poled electrodes, interrupting said current in response to a change in the flow of said fluid, and interrupting said current in response to an abnormal pressure built up in the passage for the flow of fluid.

16. The method of heating fluid by electrical conduction which comprises the steps of supplying voltages to a primary electrode and secondary electrode which forms with the primary electrode a passage for the flow of fluid, said voltages establishing a potential difference between the primary and secondary electrodes to efiect heating of said fluid, interrupting the supply of voltage to said secondary electrode in response to a change in the flow of said fluid, thereafter interrupting the supply of voltage to said primary electrode in response to the said change, and interrupting the supply of voltage to said secondary and primary electrodes in response to a pressure built up in the path of flow of said fluid.

17. A pressure and flow controlled automatic electric water heating apparatus comprising a water heating assembly including a water heating chamber having an inlet and an outlet, said outlet and inlet being adapted to connect with cold and hot water lines, an electrode structure within said heating chamber provided with a primary electrode and a plurality of secondary electrodes surrounding said primary electrode and spaced therefrom 13 to form an annular passage extending between said inlet and said outlet, a flow responsive device including a cylindrical flow chamber and a plunger slidable therein, said flow chamber being interposed in a water supply feeding into said heating chamber whereby the actual position occupied by said plunger depends on whether said supply is open or closed, an actuator cap supported at one end of said plunger and slidably received on the corresponding end of said cylindrical flow chamber, circuit means including a plurality of switching units to connect said electrodes to a voltage supply to establish a potential difference between said primary and secondary electrodes, said actuator cap being disposed in operative relation to said units to close said switching units when said Water supply line is open in a sequence wherein said units connecting said secondary electrodes to the supply are actuated before the unit connecting the primary electrode to the supply, said circuit means further including a safety switch connected in the circuit of said switching units, and said plunger having a longitudinal bore connecting said flow chamber with the atmosphere, and a piston slidable within said bore and in operative engagement with said safety switch whereby to open said safety switch upon the build up of pressure within said flow chamber beyond a predetermined point.

18. An apparatus according to claim 17, wherein said safety switch comprises an insulator base having three laterally spaced grooves, a pair of vertically spaced L-shaped strips mounted within the outermost of said grooves with their outwardly extending portions in vertically spaced relationship to each other to form a passage therebetween, a cylindrical bearing member mounted within the centermost of said grooves and extending outwardly therefrom, said bearing member on opposite sides having slots extending inwardly from the free end thereof aligned laterally with the spaces between the ends of said brackets, a plunger rod slidable within said casing, a transverse pin connected to the inner end of said plunger rod and extending outwardly through said slots intermediate the freely spaced ends of said brackets, cylindrical enlargements on the ends of said pin adapted to engage said bracket ends, spring means for normally retaining said plunger rod in an outer position with said cylindrical enlargements displaced from said bracket ends, and bracket means in engagement with said pin for normally retaining said cylindrical enlargements within said bracket ends, said bracket means being moved to an inoperative position upon displacement of the outer end of said piston rod.

19. An apparatus according to claim 18, said spring means comprising a spring sleeving said plunger rod with one end thereof in abutment with the end of said casing, and an enlarged knob on the outer end of said plunger rod in abutment with the other end of said spring.

20. An apparatus according to claim 19, wherein said bracket means includes a channel shaped bracket of U-shaped cross section pivotally connected to said casing and having stepped sides adapted to engage said pin and to release said pin upon downward displacement thereof under the action of said piston rod.

21. An apparatus according to claim 20, including a bolt extending upwardly through said casing and extending upwardly thereabove in an externally threaded portion, the inner end of said channel shaped member having an opening receiving said bolt upwardly therethrough, a first collar on said externally threaded portion, a spring on said externally threaded portion with one end in abutment with said collar and a second collar abutting the other end of said spring and screwed onto the outer end of said externally threaded portion whereby to vary the pressure adjustment of said channel shaped member.

References Cited in the file of this patent UNITED STATES PATENTS 1,999,962 DesRosiers Apr. 30, 1935 2,355,687 Van Hise Aug. 15, 1944 2,572,337 Harris Oct. 23, 1951 2,599,806 Benchemoul June 10, 1952 

